The present invention is a dental implant device designed to minimize tissue loss. The device has a plurality of connective tissue grooves on a stem portion of an abutment section and a plurality of bone locking grooves on a neck section of an implant section, wherein the implant section is proximal to the abutment section.
Dental implants are embedded in the jaw bone and serve to anchor one or more artificial teeth or dentures. Typically, the implant is set in the bone and an abutment is mounted on the implant. As is known in the art, the abutment generally has a first segment that abuts the implant and that is preferably positioned so as to lie within the connective tissue layer, a second segment that abuts the first segment and is preferably positioned so as to lie within the attached epithelial layer, and a third segment that abuts the second segment and is preferably positioned so as to lie within the sulcular epithelial layer. Each of the tissues layers are generally believed to be about 1 mm in depth.
Important to the success of such devices is the rigid anchoring of the implant in the bone, and several journal articles and patents have proposed various methods for achieving rigid anchoring (see U.S. Pat. No. 5,344,457 and incorporated herein by reference). For example, U.S. Pat. No. 4,713,003, issued to Symington et al. describes an implant that has a tapered external body, resulting in a better distribution of the stresses acting on the device in situ than is achieved with cylindrical body implants. U.S. Pat. No. 5,344,457, issued to Pilliar et al, describes an implant that has a body with a non-porous surface on the upper portion of the implant and a porous surface on the lower portion of the implant. The porous surface provides interstices into which bone is permitted to grow once the implant is accommodated within the bone.
As reported in U.S. Pat. No. 6,454,469, issued to Hollander et al, and incorporated herein by reference, it is known to provide a variety of surface effects to enhance osseo-stability of the implant within bone. In the '469 patent a device is taught that has a collar portion consisting of proximal and distal cylindrical sub-segments, one having a surface effect adapted for the promotion of growth of soft tissue and the other adapted for the promotion of bone or hard tissue growth. Specifically, the '469 patent teaches a dental implant having a distal segment with a surface that defines an ordered microgeometric repetitive surface pattern in the form of a multiplicity of alternating ridges and grooves, each having a fixed or established width in a range of about 2.0 to about 25 microns and a fixed or established depth in the range of about 2.0 to about 25 microns.
While the device of the '469 patent recognizes that bone and soft tissue react differently with implant surfaces, it fails to recognize that academic studies have demonstrated that pore sizes of 10 microns or less lead to little or no fibrous ingrowth, and that a pore size of greater than about 30 microns is needed to give right to good blood supply and blood vessel ingrowth. This ingrowth is believed to be a factor in impeding epithelial migration toward the boney region of the implant site, and the less epithelial migration into the site, the lower the probability of infection development.